Systems for detecting surface and subsurface objects have been used to detect concealed objects including, without limitation, hidden bombs, narcotics, cables, pipes, and corpses. Such systems also have been used to facilitate subsurface detection in various technology areas, such as for motion detection, seeing-through walls, archeology, and geology. Most notably, however, such systems are used to detect land mines. While systems for detecting surface or subsurface objects, including the invention described herein, may be advantageously employed in various applications, the invention is described herein, in terms of a system for the detection of land mines or other improvised explosive devices (IEDs), with no intent of limitation.
Since 1975, land-mines have exploded under more than 1 million people and are currently thought to be killing approximately 800 people a month. In 64 countries around the world, there are an estimated 10 million land-mines still lodged in the ground. They remain active for decades-years after wars have ended. As such, a large worldwide community has devoted extensive resources to ridding the world of both future and currently placed land mines. Mine detecting technology has been invaluable to this endeavor and has been responsible for preventing the loss of many lives.
There are currently at least four types of mine detection machines available: 1) vehicle mounted; 2) handheld; 3) airborne; and 4) mechanical clearing devices such as rollers, plows, or flails. These mine detection machines detect surface and subsurface anti-vehicular (“AT”) and anti-personnel (“AP”) mines. An AT mine is a type of land mine designed to damage or destroy vehicles, whereas an AP mine is used against humans.
Vehicle mounted, airborne, and mechanical clearing types of mine detection systems have value because they cover large areas and because they can have good ballistic protection or good standoff if, for example, they are remotely controlled. On the other hand, they are very expensive, very large, very heavy, and much less prevalent than handheld detection systems. In addition, mechanical clearing devices are not highly effective in detecting and clearing landmines and they tend do damage fragile ecosystems when deployed as they must destructively interact with the area they are clearing.
Handheld mine detection systems are helpful because they are inexpensive, relatively easy to use with appropriate training, easy to transport, and they are already very prevalent in the military and commercial world. However, current handheld mine detection systems require the soldier or de-miner to personally hold and sweep the sensor from side to side while walking through a hazardous environment. Thus, the soldier or de-miner risks his or her life being in such close proximity to buried explosive devices (landmines or other improvised explosive devices (IED)) which can detonate when stepped upon. Moreover, enemy fire may be directed toward the soldier engaged in de-mining. In addition, these handheld sensors must be swept at the appropriate speed and at the appropriate overlap to ensure adequate coverage so that no mines are missed by the sensor and operator. This sweep speed and overlap is an activity that requires training and experience to be proficient, let alone expedient. Mistakes can be fatal, both immediately to the operator of the sensor should he detonate a mine or later to the civilian population that will be using the recovered land should a mine have been missed.
As such, there remains a need for an improved system for employing handheld sensors to detect surface or subsurface objects that is safe, convenient, and inexpensive.